Review from Anatomy 1 Anatomy The study of the structure and shape of the body and its parts Physiology Study of how the body and its parts work or function and how the body functions both on a microscopic and macroscopic level Levels of organization Cells smallest living unit Tissues collection of cells of same type Organs collection of two or more types of tissues put together into structures that perform a specific function Organ Systems collection of organs that work together to accomplish a particular task Primary cells and Tissue classes Muscle contraction generation of force Connective connect anchor support Epithelial barrier between body and external environment exchange Nerve initiate transmit electrical impulses Body fluid Compartments A 70 kg man has a total body water of 42 Liters o 28 Liters are intracellular fluid ICF o 14 Liters are extracellular fluid ECF 3 liters plasma 11 liters interstitial fluid ISF Organ Systems Immune and Lymphatic System returns fluids to bloods vessels cleanses the blood protects the body from pathogens housekeeping Lymphatic vessels lymphatic nodes thoracic duct Transports materials in body via blood pumped by heart Cardiovascular System o oxygen o carbon dioxide o nutrients o wastes blood vessels and heart Respiratory System Keeps blood supplied with oxygen Removes carbon dioxide Maintains blood plasma pH Gas exchange Nasal cavity pharynx larynx trachea broncus left lung Urinary System Eliminates wastes Maintains acid base balance Regulates water and electrolytes Kidney ureter urinary bladder urethra Reproductive System Produces offspring Not required for homeostasis men seminal vesicles penis prostate gland vas deferens testis scrotum women mammary glands uterine tube ovary uterus vagina Digestive System Breaks down food Allows for nutrient absorption into blood Eliminates indigestible material Oral cavity esophagus stomach small intestines large intestines rectum anus Essential for life brings in nutrients Interrelationships among body systems to maintain homeostasis Homeostasis Central organizing principle of physiology Process of maintaining stable internal environment compatible for life o A dynamic state of equilibrium steady state Homeostasis steady state o Stable body temperature o Maintain blood plasma pH o Maintain blood pressure blood volume o Maintain water balance osmolarity o Stable blood sugar levels o Body weight Most organ systems contribute to homeostasis o Exception reproductive system Negative feedback look is used in homeostasis Homeostasis is necessary for normal body functioning and to sustain life Homeostatic imbalance a disturbance in homeostasis resulting in disease if not corrected Maintaining homeostasis o Receptors sensors Responds to changes in the environment stimuli Detect level of regulated variable and provide input to Sends information to control center integrating center o Control center Integrating center Determines set point usually in brain desired level of regulated variable and analyzes information Usually in the brain compares set point to actual level of regulated variable and sends output to effectors to return regulated variable toward set point Determines appropriate response o Effector provides a means for response to the stimulus Negative feedback control in homeostasis have too much make less or don t have enough make more Body s response the original stimulus is to offset it so that it is within normal physiological set points Change triggers change in a regulated variable in internal environment this triggers a reaction to oppose the detected change and return regulated variable toward normal parameters set point Effectors cause an effect to happen i e if you are too hot you sweat to release heat from body to environment Positive feedback loop Have more make more Causes a rapid increase in stimulus Not a common mechanism for maintaining homeostasis Response increases the original stimulus as opposed to canceling it out Stimulus must end for response to end o An outside source is required to shut off positive feedback cycle i e breast feeding o with negative feedback milk being made would be cancelled out to stop it from being make o with positive feedback milk is made the more the baby sucks the more milk is produces i e child birth o the harder the baby s head pushes against the cervix the more contractions occur o baby being born ends the stimulus 2 types of large hearts athletes and those with heart attacks o Heart attacks Dead heart tissue muscle tissue is replaces with scar connective tissue heart must compensate the damaged tissue by pumping harding causing the heart rate to increase heart gets bigger because the muscles get bigger from working hard more oxygen and nutrients are needed increase heart rate heart s demand increases gets bigger and pumps faster positive feedback Cycles cannot continue and is only stopped by a heart attack death doctors can give meds to slow heart rate before o Athletes Heart needs more oxygen heart rate increases no scar tissue have full capacity of heart Heart will relax when not training so the feedback stops When atheletes sleep hormones are released to increase blood flow to heart Athletes have lower resting heart rates o Difference between athletes and those with heart attacks is at rest When an athlete is resting the heart is resting When a heart attack patient is resting the heart is not at rest Blood Blood Overview The only fluid tissue in the human body Classified as connective tissue Components of blood o Living cells formed elements cells Erythrocytes RBC s transport oxygen and carbon dioxide Leukocytes WBC s defend against pathogens Platelets cell fragments formed from magakaryocytes important in blood clotting o Nonliving matrix Plasma is the fluid and solutes cyte mature cell type blood is used as a vehicle of transport color o oxygen rich scarlet red o oxygen poor dull red o blood appears blue in veins only because skin acts as a filter pH of blood 7 35 7 45 7 4 blood temperature is slightly higher than body temperature at 38 degrees celcius 100 4 farenheit o blood transfers heat through the body to skin and core organs Hematocrit Blood when blood is centrifuges erythrocytes sink to bottom leukocytes and platelets form a thin buffy coat and plasma rises to top Average blood volume o Women 5 Liters o Men 5 5 Liters Plasma o Mostly water 90 o Contains salts electrolytes minerals ions Amount of solutes in a solvent osmotic baland pure
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